Nov
21

Maths – estimating and the Inverse

Filed Under (General News) by on 21-11-2017 and tagged , , , , , , ,

Estimating 

Inverse operations

Level 1

  1. I think of a number. I multiply it by 2 and my answer is 24.  What was my number?
  2. I think of a number. I add 16 and my answer is 36.  What was my number?
  3. I think of a number. I subtract 25 and add 2.  My answer is 27, what was my number?
  4. I think of a number. I add 15 and then multiply by 2.  My answer is 32, what was my number?
  5. I think of a number. I divide by 2, add 98 and my answer is 100.  What was my number?

Level 2

  1. I think of a number. I add 15 and multiply by 2.  Then I divide by 2 and my answer is 16, what was my number?
  2. I think of a number. I divide by 2, add 98 and my answer is 100.  What was my number?
  3. I think of a number. I add 50, multiply by 3 and subtract 25.  My answer is 275.  What was my number?
  4. I think of a number. I multiply by 20, divide by 10 and subtract 5.  The answer is 195.  what was my number?
  5. I think of a number. I double it, add 31, and then subtract 4. My answer is 149, what was my number?

Level 3

  1. I think of a number. I double it, add 31, and then subtract 4. My answer is 149, what was my number?
  2. I think of a number, I multiply it by 2, and then add 9. The answer is 20.  What was my number?
  3. I think of a number, I divide by 4, add 1.5 and then double it. My answer is 23.  what was the number?
  4. I think of a number, I multiply by itself, subtract 44, add 10 and my answer is 110. What was the number?
  5. I think of a number, I subtract 35, add 5 and then multiply by 1.  My answer is 0.  What was the number?

Level 4

Your ULTIMATE challenge – For each of the calculations you have done, you now need to write these out as calculations.

Eg.   I think of a number. I multiply it by 2 and my answer is 24.  What was my number?

N x 2 = 24

YOU CAN DO IT!!!



6 Responses to “Maths – estimating and the Inverse”

  1.   20pawel Says:

    Level 1
    1. 12
    2. 20
    3. 50
    4. 1
    5. 2
    Level 2
    1. 1
    2. 20

    Reply

  2.   Antonina Says:

    LEVEL 2
    1. 1
    2. 99
    3.135

    Reply

  3.   20jacob Says:

    Level 1
    1. 12
    2. 20
    3.50
    4.1
    5.2
    Level 2
    1.1
    2.2

    Reply

  4.   20pawel Says:

    Level 2
    2. 2
    3.

    Reply

  5.   20sinju Says:

    Level 1
    1.12
    2.20
    3.50
    4.1
    5.2
    Level 2
    1.1
    2.2

    Reply

  6.   20abubakar Says:

    LEVEL 1
    1. 12
    2.20
    3.50
    4.16
    5.4
    LEVEL 2

    Reply

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